Age, Species, and Sex Determination of Four North American Hummingbirds William H. Baltosser •

Dept. of Biology New Mexico State University Las Cruces, New Mexico 88003.

The identification of female and immature Costa's (Calypte costae), Anna's (Calypte anna), Ruby- throated (Archilochus colubris), and Black-chinned (Arch//ochus a/exandr/) hummingbirds is one of the more difficult taxonomic problems among the Trochilidae. Ridgway (1892) and Coues (1903) were among the first to provide basic insights into the problem, but their analyses lacked many of the essential quantitative dat• Subse- quent works by Williamson (1956), Banks and Johnson (1961), Short and Phillips (1966), Stiles (1971), Leberman (1972), Phillips (1975, 1982), Wells et al. (1978), and Baldridge (1983) all furthered our knowledge. Nonethe- less, all failed in one way or another to identify, quantify, and/or to compare differences between species, age groups, or sexes. The present paper, while acknowled•ng the contributions of the former workers, identifies and quantifies numerous additional heretofore undescribed identification traits.

A comprehensive key, with attendant supporting dat• is presented that allows virt•mlly any specimen of these species to be correctly assigned to one of three age cate- gories (adult-older than ca. 10 months, subadult- posffledging age greater than i month but less than 10 months, and juvenile-postfiedging age less than 1 month), the appropriate species, and the proper se• Statistically significant differences demonstrate that species, age groups, and sexes are quite distinct and thus separable from one another. The existence of a diminu- tive race of the Black-chinned Hummingbird (see Phillips 1982) is confirmed, although in the present paper this is discussed only within the context of the problem this presents in identification.

Methods

A total of 821 specimens from throughout the ranges of the four species was examined. Feathers that were damaged or otherwise "ruffled" were first "smoothed" into natural position prior to measuring. The methodology for aging hummingbirds developed by Ortiz-Crespo (1972), which is based upon the presence or absence of bill

corrugations, has been refined to produce three age cate- gories (adult, subadult, and juvenile) rather than just two (immature vs adult). The presence of bill corrugations and the degree to which they occur throughout the length of the bill are the primary criteria used for aging, although these are supplemented to some extent by plumage char- acteristics. The assignment of an individual to a particu- lar age class is therefore based primarily on maturity rather than plumage.

Measurements were made using 10-cm dial calipers, accurate to the nearest 0.05 mm. Differences among species and between males and females of the same age were analyzed by subjecting all data to one-way analyses of variance (UNIVAR-D. M. Power, unpubl.). When the group F-statistic for a particular measure was significant, the sums of squares simultaneous test procedure (Gabriel and Sokal 1969) was used to determine maximally non- significant subsets. In addition, 95% confidence intervals about the mean were calculated for each character.

Variations in numerous qualitative characteristics, when relevant to identification, are presented as percentages of the sample population.

In Figure 1, quantitative measurements of primary im- portance used in this study are depicted, many of which are described in Baldwin et al. (1931). Length of exposed culmen (1A) was measured from the point where the tips of the feathers of the forehead impinge upon the culmen to the tip of the culmen. Length of wing chord (lB) was measured from the farthest anterior point on the anterior edge of the wrist joint to the tip of the longest primary (#10), without attempting to fiatten the curve of the primaries. Maximum width of the 5th teetrix (1C) was measured at the widest point from one edge of the feather to the other, at right angles to the shatk Length of white at the tip of the 5th rectrix (1D) was measured along the rachis to the tip. Tail length (1E), only to the nearest mm, was measured from the insertion of the two middle rec-

trices to the longest tail feather of the unspread tail. Length of white at the tip of the 3rd rectrix (1F) was measured in the same manner as that for the 5th rectrix.

•Current address: Dept. of Biology and Museum of Southwestern Biology, The University of New Mexico, Albuquerque, New Mexico 87131.

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Age, Species, and Sex Determination of Hummingbirds (cont.)

The maximum width of the inner web. of primary 10 (outermost-lG) was obtained by first establishing the area within 5 mm of the tip (as measured along the rathis) and then measuring the maximum width of the inner web within this area at an angle perpendicular to the rachis. The maximum width of white at the tip of the 3rd rectrix (1H) was simply measured from edge to edge (not neces- sarily perpendicular to the rachis or other portions of the feather). "Area" of white at the tip of the 3rd rectrix (a derived character not depicted) was calculated by multi- plying the length of white (1F) by its maximum width (1H).

Results and Discussion

Virtually all specimens examined in this study could easily be aged, identified to species, and sexed using the key that follows. Approximately 90% could be correctly classified using only the first two or three phrases within each couplet of the key. The additional phrases (con- densed print) are nonetheless provided to identify the remaining 10%, which for one reason or another were not otherwise separable. Characteristics that are of prime importance include: (1) the presence or absence of corm- gations on the bill (viewed under 10X magnification) in

1A

(EXPOSED CU

lB

W•NG

(CHORD)

1C

L

MAXIMUM WIDTH 5TH RECTRIX

1D

LENGTH OF WHITE 5TH RECTRIX (MEASURED ALONG RACHIS)

'•E •.. j TAIL LENGTH

(MEASURED FROM INSERTION TO TIP OF LONGEST RECTRIX)

1F LENGTH OF WHITE 3RD RECTRIX

(MEASURED ALONG RACHIS)

1G MAXIMUM WIDTH OF INNER WEB OF lOTH PRIMARY (A) WITHIN 5mm OF TIP AS MEASURED ALONG RACHIS

1H MAXIMUM WIDTH OF WHITE AT TIP OF 3RD RECTRIX

Figure L Measurements used throughout the key

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determining age; (2) the shape of the tip and width of the inner six primaries in species and sex determinations; (3) the maximum width of the 5th rectrix, whether the dark rachis extends into the white tip, and the shape of the tip in species and sex determinations; and (4) the amount of white at the tip of rectrix 3 in sex determination. Differ- ences in the amount of white at the tip ofrectrix 3 between juveniles and subadults of the same sex are, nonetheless, largely artifacts of wear since the rectrices acquired in the nest are usually retained until adult plumage is acquired at an age of about 10-11 months (Nancy Newfield in litt.). Occasionally, however, juvenile rectrices are lost prema- turely and they are replaced with adult rectrices, even in

very young birds (Nancy Newfield in litt. and present study).

The former characters and those depicted in Figure 1, in conjunction with those depicted and explained in Figure 2 that are more species and/or age specific, form the basis for the following key. Statistics pertaining to the charac- ters used in the key are presented in Appendices Specimens upon which the key is based are from through- out the entire ranges of the four species and thus the key should be relatively free of geographic or seasonal bias. A listing of the specimens upon which the key is based is available from the author upon request•

Key to Age, Species, and Sex Determination of Four North American Hummingbirds

2A Side View

JUVENILE' BILL '-i;• CORRUGATIONS PRESENT, DEEPLY INCISED AND THUS VERY OBVIOUS. AND GENERALLY EXTENDING THROUGHOUT THE LENGTH OF THE BILL

Bill corrugations deeply incised throughout the length of bill (Fig. 2A); feathers on nape and back extensively edged with buffy or grayish-JUVENiLE BIRDS ....................................................... 18

lb. Bill corrugations either absent or shallow and restricted to posterior portion of bill ............................................................ 2

Bill corrugations at least faintly visible (Fig. 2B)-SUBADULT BIRDS .................................................................................... 11

Side View

2 B Y2 .. •.• SUBADULT- BILL CORRUGATIONS SHALLOW AND THUS LESS OBVIOUS, GENERALLY NOT EXTENDING TO ANTERIOR PORTIONS OF

BILL• OLDER SUBADULTS MAY LACK CORRUGATIONS

2b.

3a.

3b.

Bill corrugations absent (Fig. 2C) ........................................... 3

Despite the absence of bill corrugations, portions of plumage not that of an adult (i.e., birds that have been out of the nest in excess of three months but have not assumed full adult plumage; see condensed print under 3b for adult traits)-SUBADULT BIRDS

Plumage that of an adult (see condensed print below) ADULT BIRDS ........................................................................................... 4

2C Side View

ADULT- BILL CORRUGATIONS ABSENT, BILL SMOOTHLY

POLISHED• A FEW INHERENT GROOVES RUNNING PARALLEL TO BILL OCCASIONALLY VISIBLE BUT THESE ARE NOT CORRUGATIONS

Adult plumage with regard to males includes fully featherod metallic crown in Ccdypte eostae and C. anna, fully featherod rc•tallic gorget in the former two spedes and in Archilochus colubris and A• a/exandr/, and in males of all four spedes the outer rectrices not tipped with white.

Adult plumage in female birds, par[icularly as compared to older subadults (i.e., tho•e lacking bill corrugations), is less easily discerned because subadult and juvenile birds all resemble adult females (i.e., not as above). UNT/L ONE BECOMES FAM/L/AR W/TH THE KEY, treat all birds lacking bill corrugations and not exhibiting the following traits as adults, rather than subadults:

(1) Rounded secondaries (Fig. 21)) are indicative of subadult and juvenile aged birdsinC. anna.

2D

SHAPE OF SECONDARIES IN ADULT (A) AND YOUNG (B) C. ANNA

(2) Scattered metallic feathers in the crown and the extension of the dark rschis into the white tips of the outer rectricos (Fig• 2E and 2F) of C. costae and C. anna are indicative of young males.

(3) Scattered metallic roddish/gold feathers on the throat and the shape of primary 6 (Fig. 2G) in A• co/ubr/s are indicative of young males.

(4) Completely black and metallic purple feathers scattered throughout the throat are indicative of young male .4. a/extmdr/; scattomd purple feathers in the

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Age, Species, and Sex Determination of Hummingbirds (cont.)

2E

PATTERN OF BLACK AT • THE TIP OF RECTRICES A 5,4, AND 3 IN C. COSTAE- DARK RACHIS ENTERS

WHITE TIP IN MALE (A) • BUT NOT THAT OF -- FEMALE (B) B

absence of solid black feathers are indicative of young male A_ dexandr/or adult female and young male C. costae.

ADULT BIRDS

4a. Crown and throat covered completely by metallic purple/violet or reddish/magenta feathers ........................................................... 5

4b. Crown not as above; throat may or may not be covered completely by metallic feathers ........................................................................ 6

2F

PATTERN OF BLACK AT THE TIP OF RECTRICES 5 AND 4 IN C. ANNA- DARK RACHIS ENTERS WHITE TIP IN MALE (A) BUT NOT THAT OF FEMALE (B)

2G

A •,' • A. COLUBRIS 6TH PRIMARY•OUTER WEB VIRTUALLY ABSENT, TIP POINTED-MALE(A)

A. COLUBRIS 6TH PRIMARy• OUTER WEB DECIDEDLY PRESENT, TIP LESS POINTED-FEMALE(B)

Crown and throat covered completely by metallic purple/violet feathers-Adult Male Calypte costae.

Crown and throat covered completely by metallic reddish/ma- genta feathers-Adult Male Calypte anna.

Entire throat either metallic reddish/gold or black edged with metallic purple feathers .............................................................. 7

Throat may or may not possess metallic feathers; if metallic feathers are present, then they never completely cover throat to produce a true gorget; if throat lacks metallic feathers, then throat may totally lack markings or possess varying degrees of streaking ...................................................................................... 8

Throat completely covered with metallic reddish/gold feathers- Adult Male Archilochus colubris.

Throat black on anterior half to two-thirds and metallic purple on posterior portions-Adult Male Archilochus alexandri.

2H

WIDTH OF INNER PRIMARIES APPROXIMATELY EQUAL TO OR GREATER IN WIDTH THAN OUTER PRIMARIES-CALYPTE

Inner primaries approximately equal to or greater in width than outer primaries (Fig. 2H)-Genus Calypte .................................. 9

Inner six primaries much narrower than outer four (Fig. 21)- Genus Archilochus ....................................................................... 10

Maximum width of rectrix 5 usually between 3.57 and 3.75 mm, ranging from 2.90 to 4.25 mm (Appendix A); throat of many individuals (56%) lacks purpleAriolet metallic feathers, although in an almost equal number (44%) such feathers are present-Adult Female Calypte costae.

2I

WIDTH OF INNER PRIMARIES MUCH NARROWER THAN OUTER FOUR PRIMARIES' ARCHILOCHUS

9b.

Excluding metallic purpl•Molet feathers, throat generally (89%) lacks mark- ings, but in a limited fiumher of individuals (11%) throat contains a few isolated greenish/brown feathers; wing length usually between 44.38 and 44.90 mm, ranging from 42.30 to 46.60 mm (Appendix A).

Maximum width of rectrix 5 usually between 5.54 and 5.72 mm, ranging from 4.90 to 6.75 mm (Appendix A); threat usually contains at least a few metallic reddish/magenta feathers, or if not, then at least a few relatively broad greenish/brown feathers are present-Adult Female Calypte anna.

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2J

SHAPE OF lOTH PRIMARY IN A. ALEXANDRI (A) AND A, GOLUBRIS

2K

VARIATION IN SHAPE AND RELATIVE LENGTH OF 'ARC'AT TIP OF INNER PRIMARIES OF

A. COLUBRIS

2L

AD. VARIATION IN SHAPE • MALE AND RELATIVE LENGTH OF AD. FEMALE 'ARC' AT TIP OF & YOUNG INNER PRIMARIES MALE

OF A. ALEXANDRI YOUNG FEMALE

2M

SHAPE OF 5TH RECTRIX IN A. 6LE•ANDRI-TIP

POINTED AND/OR EMARGINATED IN ADULT FEMALE AND YOUNG MALE(A-B)• TIP ROUNDED• AND NOT EMARGINATED IN YOUNG FEMALE(C)

2N : :

SHAPE AND RELATIVE • LENGTH OF 'ARC '•AT ' TIP OF INNER PRIMARIES IN C. COSTAE AND C_.. ANNA

Throat only rarely (15%) lacks either metallic x•ldish/magenta cr broad green- ish/brown feathers; wing length usually between 49.39 and 49•5 ram, taxing from 47.05 to 51•5 mm (Appendix A).

10a. Maximum width of inner web of primary 10 within 5 mm of tip generally between 2.05 and 2.20 mm, ranging from 1.60 to 2.50 mm (see Figs. 1G and 2J); forehead and crown generally greenish; exposed culmen generally between 17.19 and 17.53 mm, ranging from 15.05 to 19.30 mm (Appendix A)-Adult Female Archilochus colubris.

Throat markings virlalally absent (>95%) or when present (<5%) very faint; •ard' formed at tip of innea, primaries relatively long and gradual, producing tip that is relatively narrow and pointed (Fig. 2K); at least many of the innea, six primaries deeply notched in the majority of individuals (Fig. 2K), or if not, then long-gradual "are • at tip nonethelem present (Fig. 2K); outer web of primary 6 deddedly present (Fig. 2G); outer three reefrims and sometimes outer four (AMOUNT OF WHITE AT TIP OF •CES 3 AND 2 NOT CONSIffIENT IN ADULTS) tipped with white.

10b. Maximum width of inner web of primary 10 within 5 mm of tip generally between 3.10 and 3.20 mm, ranging from 2.65 to 3.55 mm (see Figs. 1G and 2J); forehead and crown generally brownish/gray; exposed culmen of most United States specimens generally between 20.24 and 20.54 mm, ranging from 19.00 to 22.05 mm (Appendices A and B); exposed culmen of a diminutive race that occurs primarily in Mexico is generally between 18.56 and 18.92 mm, ranging from 17.80 to 19.40 mm (Appendix B)- Adult Female Archilochus alexandri.* (See note at end of key.)

Throat of most individuals faintly streaked (75%), only occasionally (25%) are streaks of rr•derate to heavy intensity present; metallic throat feathers absent in the vast majority of individuais (95%), although one or two black feathers are present in a limited number of birds (5%) that appear to be very old; slight notch at tip of trailing edge of most inner primaries generally visible, although less discernible than in adult males (Fig. 2L); "a•Y' formed at tip of inner primaries relatively short and angular, producing tip that is relatively broad and blunt (Fig. 2L); outer three tactrims and sometimes outer four (AMOUNT OF WHITE AT TIP OF RI•CTRICF• 3 AND 2 NOT CONSISTENT IN ADULTS) tipped with white; rectrix 5 pointed and/or emarginated at tip (Fig. 2M).

SUBADULT BIRDS

11a. Maximum width of rectrix 5 almost always less than 4.25 mm (Appendix C); inner primaries approximately equal to or greater in width than outer primaries (Fig. 2H); "arc" formed at tip of inner primaries relatively short and rounded with no angular notches (Fig. 2N)-Subadult Calypte eostae .............................. 14

lib. Maximum width of rectrix 5 always greater than 4.45 mm (Appendices D, E, and F); inner primaries may or may not be equal to or greater in width than outer primaries (Figs. 2It and 2I); "arc" formed at tip of inner primaries variable, angular notches may or may not be present (Figs. 2K, 2I• and 2N)...12

12a. Wing length generally less than 46.34 mm, ranging from 40.00 to 48.50 mm (Appendices E and F); inner primaries much nar- rower than outer four (Fig. 2I) .................................................. 13

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Age, Species, and Sex Determination of Hummingbirds (cont.)

12b. Wing length usually between 49.36 and 50.18 mn% ranging from 47.45 to 52.65 mm (Appendix D); inner primaries approximately equal to or greater in width than outer primaries (Fig. 2H)- Subadult Calypte anna ............................................................ 15

Most secondaries net truncated or pointed centrally (Fig. 2D); throat usually contains at least a few metallic reddish/magenta feathers, or if net, then at least a few rather broad greenish/brown feathem present.

13a. Maximum width of inner web of primary 10 within 5 mm of tip generally less than 2.50 mm (see Figs. 1G and 2J)-Subadult Archilochus colubris ..................................................................... 16

"Ard' fortred at tip of inner primaries relatively long and gradual, producing tip that is relatively narrow and pointed (Fig. 2K); at least many of the inner six primaries in both males and females deeply netched in the majority of birds (Fig. 2K), or if net, then long-gradual "arc" at tip nenetheless pre•nt (Fig. 2K).

13b. Maximum width of inner web of primary 10 within 5 mm of tip generally greater than 2.50 mm (see Figs. 1G and 2J)-Subadult Archilochus alexandri ............................................................... 17

'Ard' formed at tip of inner primaries relatively short and angular, producing tip that is relatively broad and blunt (Fig. 2L); shape of inner six primaries (i•., notches) not as above.

14a. Outer rectrices resemble those of adult female (i.e., tipped with white); "area" of white at tip ofrectrix 3 usually between 13.39 and 15.75 mm, ranging from 9.79 to 18.63 mm (Appendix C)-Subadult Female Calypte costae.

Crown greenish or greenish/brown, ne metallic purple/violet feathers; throat contains no purple, greenish, or purple/brown feathem, brown streaks rarely present (<5%); dark inchis of outer three rectrices claes not enter white tips (Fig. 2E); rectrix 2 generally (95%) tipped with white; maximum width of rectrix 5 usually between 4.07 and 421 mn% ranging fi•om 3.70 to 4.30 mm (Appendix C).

14b. Outer rectrices may or may not resemble adult female; if not those of an adult male (i.e., lacking white tips), then "area" of white at tip of rectrix 3 usually between 2.34 and 4.02 mm, ranging from 0.00 to 9.25 mm (Appendix C)-Subadult Male Calypte costae.

Crown may lack • purple/violet feathers, in which case cobration is greenish or greenish/brown, but ff metallic feathem are present, coverage is generally incomplete; throat generally contains numerous metal• purplaMolet feathers, coverage is usually incomplete, although occasionally complete; dark rachis of outer three rectrices frequently (86%) extends into white tips (Fig. 2E); the few birds in which the extension of the dark rachis into the white tips of at least one of the outer'rectrices is not clearly visible are still separable fi•om females of the same age or younger by the reduced arntmnt of white at the tip of rectrix 3 (Appendix C); metfix 2 net tipped with white; maximum width of ratfix 5 usually between 3.43 and 3.57 rnm, ranging fi•orn 2.90 to 4.00 mm (Appendix C).

15a. Outer rectrices resemble those of adult female (i.e., tipped with white); "area" of white at tip ofrectrix 3 usually between 6.85 and 9.95 mm, ranging from 1.53 to 22.61 mm (Appendix D); dark rachis of outer three rectrices does not enter white tips (Fig. 2F)- Subadult Female Calypte anna.

Page 156 North American Bird Bander Vol. 12, No. 4

Crown greenish or greenish/brown, no metallic reddish/magenta feathers; throat generally contains at least a few n•tallic mclclish/magenta feathers, or if nog then at least a few rather breed gmenistYbrown feathers are present (86%); only rarely dees throat lack metallic or greenish/brown feathers; extent of white at tip of rectrix 3 reduced, especially in some birds, but stin more extensive than in the limited number of males that share this trait (Appendix D); rectrix 2 generally (83%) not tipped with white.

15b. Outer rectrices may or may not resemble adult female; if not those of an adult male (i.e., lacking white tips), then "area" of white at tip of rectrix 3 usually between 0.02 and 0.08 mm, ranging from 0.00 to 0.62 mm (Appendix D); dark rachis of outer two rectrices extends into white tips (Fig. 2F)-Subadult Male Calypte anna.

Crown may lack metallic reddish/magenta feathers, in which case coloration is greenish or greenish/brown, but if metallic feathers are present, coverage is generally incomplete; throat generally contains numerous metallic reddish/ magenta feathers, coverage is usually incomplete, although ay.•sionally com- plete; teetrix 3 generally not tipped with white in subadult males, but if present, white greatly /•lucecl when cornpared to females of the same age or younger, rectrix 2 not tipped with white.

Outer rectrices resemble those of adult female (i.e., tipped with white); "area" of white at tip of rectrix 3 usually between 12.86 and 15.52 mm, ranging from 8.67 to 20.87 mm (Appendix E); outer web of primary 6 decidedly present (Fig. 2G)-Subadult Female Archilochus colubris.

Metallic reddish/gold feathers absent from throat; throat usually not streaked (89%), but when streaked (11%), streaking generally very faint; rectrix 2 generally (81%) tipped with white.

16b. Outer rectrices may or may not resemble adult female; if not those of an adult male (i.e., lacking white tips), then "area" of white at tip of rectrix 3 usually between 3.29 and 4.53 ram, ranging from 0.01 to 9.68 mm (Appendix E); outer web of primary 6 virtually absent (Fig. 2G)-Subadult Male Archilochus colubris.

One or two metallic roddish/gold feathers usually present (>95%) on throat, remaining areas rmderately to heavily streaked in r•st birds (91%); inctrix 2 not tipped with white.

17m Outer rectrices resemble those of adult female except that rectrix 5 (outermost) not pointed or emarginated at tip as in most adult females and young males (Fig. 2M); "area" of white at tip of rectrix 3 usually between 17.60 and 20.06 mm, ranging from 10.01 to 28.07 mm (Appendix F)-Subadult Female Archilochus alexandri.

Black and/or metallic purple feathers absent from throat; throat usually (81%) at least very faintly streaked, only occasionally (196/o) are streaks of moderate to heavy intensity present; trailing edge of inner primaries generally lacks minute r•teh that is present in at least sorr• of the inner six primaries of adult females and young males (Fig. 2L); inctrix 2 generally (87%) tipped with white.

17b. Outer rectrices may or may not resemble adult female; if not those of an adult male (i.e., lacking white tips), then the tip of rectrix 5 (outermost) generally pointed and/or emarginated (Fig. 2M); "area" of white at tip of rectrix 3 usually between 4.63 and

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Age, Species, and Sex Determination of Hummingbirds (cont.)

6.15 mm, ranging from 1.84 to 9.45 mm (Appendix F)-Subadult Male Archilochus alexandri.

One or two black and/or metal•c purple feathers usually present (80%) on throat, remaining areas mederarely to heavily streaked in n•st birds (87%); trailing edge of inner primaries usually minutely notched (Fig. 2L); rectrix 2 very rarely (3%) tipped with white.

JUVENILE BIRDS

18a. Maximum width of rectrix 5 generally less than 4.17 mm (Appendices G, H, I, and J); inner primaries approximately equal to or greater in width than outer primaries (Fig. 2H); "arc" formed at tip of inner primaries relatively short and rounded with no angular notches (Fig. 2N)-Juvenile Calypte costae ................ 21

18b. Maximum width of rectrix 5 always greator than 4.45 mm (Appendices G, H, I, and J); inner primaries may or may not be equal to or greater in width than outer primaries (Figs. 2H and 2I); "arc" formed at tip of inner primaries variable, angular notches may or may not be present (Figs. 2I• 2L, and 2N)...19

19a. Wing length generally less than 48.00 mm, ranging from 37.25 to 48.50 mm (Appendices I and J); inner six primaries much nar- rower than outer four (Fig. 2I) ................................................... 20

19b. Vfmg length generally greater than 48.00 mm, ranging from 47.10 to 52.25 mm (Appendix H); inner primaries approximately equal to or greater in width than outer primaries (Fig. 2H)- Juvenile Calypte anna ................................................................. 22

20• Maximum width of inner web of primary 10 within 5 mm of tip generally less than 2.50 mm (see Figs. 1G and 2J)-Juvenile Archilochus colubris .................................................................. 23

'Am • lbrmed at tip of inner primaries relatively long and gradual, producing tip that is relatively oarrow and pointed (Fig. 2K); at least many of the inner six primaries in both males and females are deeply notched in the majority of birds (Fig. 2K), or if not, then long-gradual 'a• at tip nonetheless present (Fig. 2K).

20b. Maximum width of inner web of primary 10 within 5 mm of tip generally greater than 2.50 mm (see Figs. 1G and 2M)--Juvenile Archilochus alexandri ................................................................. 24

'Am nformed at tip of inner primaries relatively short and angular, producing tip that is relatively bread and blunt (Fig. 2L); shape of inner six primaries (i.e., notches) not as above.

21a. "Area" of whito at tip of rectrix 3 usually between 11.29 and 16.15 mm, ranging from 6.30 to 22.92 mm (Appendix G)-Juvenile Female Calypte eostae.

Throat contains no purple, greenish, or purple/brown feathers, brown streaks rarely present (<5%); dark rachis of outer three rectrices does not enter white tips (Fig. 2E); inctrix 2 generally (92%) tipped with white; maximum width of rectrix 5 usually herween 3•5 and 4.17 ram, ranging from 3.50 to 4.45 mm (Appendix G).

Page 158 North American Bird Bander Vol. 12, No. 4

2lb. "Area" of white at tip of rectrix 3 usually between 3.53 and 5.61 nun, ranging from 0.15 to 9.95 nun (Appendix G)-Juvenile Male Calypte a•tae.

Throat almast always (>95%) contains at least a few metallic pur•olet feathers; dark rachis of outer three tactrices usually (>95%) ex•ends into white tips (Fig. 2E); the few indivkhals in which the extension of the dark rachis into the white tips of st lesst one of the outer tactrices is not clearly visible are stin separable from females of the same age or older by the reduced amount of white st the tip of inctrix 3 (Appendix G);, rectrix 2 generally (88%) not tipped with white; maximum width of rectrix 5 usually between 3.07 and 3.37 mm, ranging from 2.40 to 325 mm (Appendix G).

22a. Dark rachis of outer three rectrices does not enter white tips (Fig. 2F); "area"of white at tip of rectrix 3 usually between 5.53 and 10.43 mm, ranging from 1.44 to 13.20 mm (extent of white at tip of rectrix 3 reduced in some birds, but still more extensive than in subadult and juvenile males-Appendix H)-Juvenile Female Calypte anna.

Thm• may or may not contain metallic mddisWmagenta feathers or rather broad greenish/brown feathers, but if present, then limited in number, recCrix 2 may (44%) or may not (56%) be tipped with white.

22b. Dark rachis of outer two rectrices extends into white tips (Fig. 2F); "area" of white at tip of rectrix 3 presumably resembles that of subadult males (i.e., usually between 0.02 and 0.08 mm, ranging from 0.00 to 0.62 mm-see Appendices D and H)-Juvenile Male Ca/ypte anna.

Throst may or may not contain metallic mddisWmsgenta feathers or rather broad greenish/brown feathers, but if present, then limited in number;, rectrix 2 occasionally (25%) contains a trace of white st the tip, but this undoubf•l]y wears off almast imrr•diately • 'fiedging.

23a. "Area"of white at tip of rectrix 3 usually between 14.12 and 15.54 ram, ranging from 10.62 to 17.97 mm (Appendix I); outer web of primary 6 decidedly present (Fig. 2G)-Juvenile Female Archi-

Throat contains no metallic •ddish/gold leathers and only rarely (6%) are streaks present, the latter of which are usually very faint; rectrix 2 generally (81%) tipped with whit•

23b. "Area"of white at tip of rectrix 3 usually between 4.14 and 5.50 mm, ranging from 1.15 to 7.40 mm (Appendix I); outer web of primary 6 virtually absent (Fig. 2G)-Juvenile Male Archilochus colubris.

Throat generally (84%) contains no metallic reddish/gold feathers, but occa•on- ally (16%) the•e are one or two such feathers emer•'n• throat moderately to heavily streaked in most (76%) birds; rectrix 2 generally (>95%) not tipped with white.

24• "Area" of white at tip of rectrix 3 usually between 17.67 and 21.17 nun, ranging from 12.73 to 24.00 mm (Appendix J); rectrix 5 (outermost) not pointed or emarginated at tip as in most adult females and young males (Fig. 2M)-Juvenile Female Archilochus alexandri.

Oct.-Dec. 1987 North American Bird Bander Page 159

Age, Species, and Sex Determination of Hummingbirds (cont.) Blsck and/or n•ta]lic purple feathers absent from thruat; throat usually (89%) at least very faintly streaked, only occa•onally (11%) are streaks of moderate to heavy intensity present; trailing edge of inner primaries lacks minute notch that is present in at least some of the inner six primarie• of sdult females and young ms]es (Fig. 2L); rectrix 2 tipped with white.

24b. "Area • of white at tip of rectrix 3 usually between 6.17 and 8.55 mm, ranging from 3.40 to 12.00 mm (Appendix J); rectrix 5 (outermost) generally pointed and/or emarginated at tip (Fig. 2M)-Juvenile Male Arch//ochus a/exandr/.

Blsck and/or metallic purple feathers frequently absent (61%) from throat, but occa•onal• (39%) one or two such feathers emerging;, throat rrg•erately to heavily streaked in mast individuals (83%); minute notch at tip of trailing edge of ma• inner primarie• generally visible (Fig. 2L); rectrix 2 occasionally (39%) has trace of white at tip, but this undoubtedly wears off very scan ai•er fiedging.

Note

The diminutive race ofA• a/exandr/is at least occasionally sympa- tric with A co/ubr/s during winter and migration. Excluding adult males that are easily distinguished, the diminutive race of A• a/exandr/is separable from,• co/ubr/s on the basis of(1) the width and subsequent shape of the inner web of primary 10 (outermost), (2) the shape of the inner primaries, and (3) on the basis of forehead and crown coloration.

1. In the diminutive race (as well as in the large race) of A a/exandr/, the maximum width of the inner web of primary 10 within 5 mm of the tip is greater than 2.50 mm (small race • = 3.07, s.d. = 0.19, range 2.65 to 3.40; large race • = 3.22, s.d. = 0.18, range 2.95 to 3.55) and thus more asymmetrically "club-shaped"than A• co/ubr/s (see Figs. 1G and 2J). In contrast, the maximum width of the inner web of primary !0 within 5 mm of the tip in A colubris is less than 2.50 mm (• = 2.13, s.d. = 0.17, range !.60 to 2.50), which produces a more slender "knife-shaped"tip (see Figs. 1G and 2J).

2. There is only a minute notch, and this is not always clearly visible in birds with worn plumage, at the tip of the trailing edge of many of the inner six primaries of males of all ages and adult female A a/exandr/(both races-see Fig. 2L). The "arc" formed at the tip of the inner six primaries in the diminutive race, as well as the large race, ofA• a/exandr/is relatively short and angular, which produces a tip that is relatively broad and blunt (Fig. 2L). In A• co/ubr/s, there is generally a deeply incised notch at the tip of the trailing edge of most of the inner six primaries (Fig. 2K). The few A• co/ubr/s lacking the deeply incised notch at the trailing edge of the inner primaries are still separable from the small, as well as the large, race of A• a/exandr/of all ages and sex on the basis of the longer "arc" at the tip of the inner primaries, which produces a relatively narrow and pointed tip (Fig. 2K), rather than the relatively broad and blunt tip found in both races of A• a/exandr/ (Fig. 2L).

3. In A a/exandr/(both races) the forehead and crown in adult females is generally brownish/gray, whereas in A• colubris it is usually more greenish.

Page 160 North American Bird Bander Vol. 12, No. 4

Acknowledgments

I am especially grateful to the following curators and their staff for their assistance in the loan of specimens: Frank Gill and Mark Robbins (Academy of Natural Sciences of Philadelphia); Lester Short and John Bull (American Museum of Natural History); Luis Bapfista and Stephen Bailey (California Academy of Sciences); David Niles (Delaware Museum of Natural History); John Hafner (Moore Laboratory of Zoology-Occidental College); Terry Merkel and Jan Scott (Museum of Northern Arizona); Ralph Raitt (New Mexico State University); Amadeo Rea (San Diego Natural History Museum); Stephen Russell and Tom Huels (University of Arizona-Dept, Ecology & Evolutionary Biology); Ned Johnson (university of Cali- fornia-Museum of Vertebrate Zoology); Robert Storer (university of Michigan-Museum of Zoology); and Rich- ard Zusi, Storrs Olson, and Bonnie Farmer (U.S. National Museum of Natural History-Smithsonian Institution). I thank John P. Hubbard, Troy L Be• and Ralph J. Raitt for critically reviewing initial dragcs of this manuscript. Subsequent reviews by William P• Calder III, Nancy L Newfield, Allan R, Phillips, and Robert C. Tweit are sincerely appreciated. Other individuals to whom I am extremely grateful include my wife Ginger and my daughter Dianna. The privileges extended to me by the U.S. Fish and Wildlife Service and the State of New

Mexico, which allowed me to capture, band, and to collect birds are greatly appreciated. Many of the initial portions of this study were supported indirectly by the New Mexico State University Department of Biology, the New Mexico Department of Game and Fish, and Chapman Memorial grants (61462, 84472, and 110115) from the American Museum of Natural History.

Literature Cited

Baldridge, F.A. 1983. Plumage characteristics of juve- nile Black-ehinned Hummingbirds. Condor 85:102- 105.

Baldwin, S. P., H. C. Oberholser, and L G. Worley. 1931. Measurements of birds. Scientific Publications of the

Cleveland Museum of Natural History Vol. 1I: ix + 165 pp.

Banks, K C. and N. IC Johnson. 1961. A review of North American hybrid. hummingbirds. Condor 63:3-28.

Coues, E. 1903. Key to North American birds. Fifth edition. Dana Estes and Co., Boston. Vol. 2: vi + 537-

1152 pp.

Gabriel, K R, and R, R, Sokal. 1969. A new statistical approach to g•ographic variation analysi• Systematic Zoology 18'9.59-278.

Leberman, R, C. 1972. Identify, sex, and age it. Key to age and sex determination of Ruby-throated Hum- mingbirds in autumn. Inland Bird Banding News 44:197-202.

Ortiz-Crespo, F. I. 1972. A new method to separate immature and adult hummingbirds. Auk 89:851-857.

Phillips, A• R, 1975. Why neglect the difficult? Western Birds 6:69-86.

Phillips, A. R, 1982. Hummingbirds. Pp. 1144 in Charles Chase HI (editor). Third Denver Museum of Natural History and Colorado Field Ornithologists' taxonomy clinic. Colorado Field Ornithologists' Jour- nal 16:5-15.

Ridgway, R, 1892. The Humming Birds. Smithsonian Institution. United States National Museum (from the report of the National Museum for 1890, pages 253- 383). Washington, D.C.

Short, L L. and A. R, Phillips. 1966. hummingbirds from the United States. 265.

More hybrid Auk 83'9.53-

Stiles, F. G. 1971. On the field identification of California hummingbirds. California Birds 2:41-54.

Wells, S., R, A. Bradley, and K F. Baptista. 1978. Hybridization in Calypte hummingbirds. Auk 95:537- 549.

Williamson, F. S. L 1956. The moult and testis cycles of the Anna Hummingbir& Condor 58:342-366.

(Western Bird Banding Association)

(Appendices on following pages)

Oct.-Dec. 1987 North American Bird Bander Page 161

Age, Species, and Sex Determination of Hummingbirds (cont.)

APPENDIX A. Meaeuremente (mm) of adult female Caere*e, Ann&Oe, Ruby-throated, &nd Hlack-chlnned hummingblrde. Significant differencee between epeclee depicted by letter groupings (I.e., 0 ACR

lndicatee that Black-chine (H) differ elgniflcant]¾ from Coeta'e (C), Anne'e (A), end Rub¾- throate (R); the latter three of which do not differ elgnlfJcantl¾ from each other).

Character Stetletlce Costa'e Anne•e Ruby-throated Black-thinned Significance

HJJ] i ]7.59 17.03 17.36 20,39 SJg, P(O.OI (exp. culmen) S.D. 0.55 0.73 0.79 O,69

N 63 70 83 82 (F = 336,68) RANGE 10.40-10.65 16.20-19.00 15.05-]9.30 ]9.OO-22.05

95• C.X. ]7.45-]7.73 17.46-]7.80 ]7,]9-17,53 20.24-20.54 H ACR

Mlng • 44.64 49.02 44.46 46,14 SJg. P(O,OI (chord) S.D. ].o5 ].00 1.o7 1.10

N 63 77 8! 82 {F = 388.67) RANGE 42.30-46,60 47.05-51.85 41.90-47.40 43,60-48.30

95• C.I. 44.38-44.90 49.39-49.85 44.21-44.69 45.90-46.38 A H CR

Tell • 23.26 26.52 25.4] 26.10 Slg. P(O.OI (length) S.d. 0.96 ].04 0.83 0,87

N 60 79 82 81 (F = 169,57) RANGE 2].00-25.00 24.00-29.00 23.00-27.00 24.00-29.00

95• C.I. 23.02-24.50 26,29-26.75 25.23-25.59 25.91-26.29 A B R C

MeXllUl width • 3.66 5.63 6.34 5.10 Slg. P(O.01 5th rectrix S.D. 0.34 0.39 0.29 0.28

N 64 ?? 73 79 {F = 479.79) RANGE 2.90-4.25 4.90-6.76 4.60-6.20 4.25-5.85

95• C.X. 3.õ7-3.7õ 5.54-5.72 5.27-5.41 5.O4-5.16 A R B C

Length of white i 5.69 5.84 6.86 6.42 $]g. P(O.OI 5th rectrlx $.D. 0.77 0.66 0.89 0.69

N 64 77 72 78 (F = 36.o2) RANGE 3.65-7.10 4.15-7.16 4.55-8.90 4.80-8.55

95• C.I. 8.50-5.88 5,69-5.99 8.65-7,07 6.26-6.88 R B AC

APPENDIR B. Meaeuremente (mm) of adult fem&]e Black-chlnned Hummingbirds ehowlng elgnlflcent differences between the large and emal] recee of this spacica.

98•

Character Confidence Significance Race • S.D. N Range Interval (large ve smell)

Bill (expoeed culmen)

Large race 20.39 0.09 02 19.00-22.05 20,24-20,54 Slg. P(O.OI

Smell race 18.74 0.53 36 17.80-19.40 18.56-18.92 (E - 163.94)

H]ng (chord)

Large race 46.14 1.10 82 43.60-48.30 45.90-46.38 Slg, P(O.O1

Smell race 44.72 1.20 36 41,95-46.90 44.31-45.13 {F = 39.92)

Tell (length)

Large race 26.10 0.87 81 24.00-29.00 25.91-26.29 Slg. P(0.01

Small race 25.36 0.96 36 24.00-28.00 25.03-25.69 {F - 16.67)

Maximum width 5th rectrlx

Large race 8.10 0.28 79 4.25-5.85 5.O4-5.16 NS

Smell race 5.03 0.16 32 4.65-5.45 4.97-5.09 (F = 1.54)

Length of white 6th rectrlx

Large race 6.42 0.69 78 4.80-8.85 5.26-6,58 NS

Small rece 6.21 0.70 32 5.25-7.83 5.96-6.46 (r = 2.OI)

Page 162 North American Bird Bander Vol. 12, No. 4

APPENDIX C. Measurements (mm! of subadul• Costa•s Hummingbirds showing significant differences between sexes.

95E

Character Confidence Significance Sex • S.C. M Range interval (female vs male)

B111 (exposed culmen)

Female

Male

Ming (chord)

Female

Hale

Tall (length)

Female

Male

Maximum width 5th FactFiX

Female

Hale

Length of white 5th rectrJx

Female

Male

Area of whJtB 3rd rectrJx

Female

Male

17.11 O.61 24 16.O5-18,30 16.85-17.37 sag. P<O.O]

16.47 0.59 50 16.26-17.80 16.31-16.65 (F • 17.971

44.41 1.O1 24 41.90-46.20 43.98-44.84 MS

44.16 0.95 50 42.30-46.75 43.89-44.43 (F = 0.99)

23.13 0.90 24 21.00-25.00 22.75-23.51 SJg. P(O.O]

22,55 0.73 61 21.OO-24.OO 22.34-22.76 (F = 8.73)

4.14 0.17 24 3.70-4.30 4.07-4.21 Slg. P•O.OI

3.50 0.24 46 2.90-4.00 3.43-3.57 (F ' 134.92)

5.19 0.68 24 4.10-5.60 4.90-5.48 Slg. P*O.O]

3.78 0.70 46 2.30-5.60 3.57-3.99 (F ' 65.59)

14.57 2.79 24 9.79-]8,63 13.39-15.76 sag. P(O.OI

3,18 2.75 44 0.00-9.25 2.34-4.02 (F = 263.161

APPENDIX D. Measurements (mm) of Bubadult Annaes Hummingbirds showing significant differences between sexes.

95E

Character Confidence Significance Sex • S.C. M Range Interval (feeale vs male)

Bill (exposed cuJmen)

Female 17.71 O.70 36 15.90-18.75 17.47-17.95 NS

Male 17.59 0.73 63 16.OO-19.OO 17.41-17.77 (F = 0.72)

Ming (chord)

Female 49.77 ].]7 34 48.OO-52.65 49.36-50.18 MS

Male 49.74 0.93 62 47.45-5].90 49.50-49.98 (F m 0.06)

Tall (length)

Female 27.06 0.79 36 28,00-29.00 26.79-27.33 NS

Male 26.96 O.55 50 25.OO-29.OO 26.71-27.21 (F - 0.26)

Maximum width 5th FaCtFiX

Female 6.98 0.38 35 8.30-6.95 5.86-6,]O NS

Male 5.87 0.31 49 6.20-6.50 5.78-5.96 (F" ].981

Length of white 5tb FactFix

Female 5.50 0.73 35 4.15-6.85 5.34-5.84 Slg. P(O.01

Male 3.48 0.70 48 1.60-5.25 3.28-3.68 (F = 176.861

Area of white 3rd rectrJx

Female 8.40 4.58 36 1.53-22.61 6.85-9.95 Slg. P(O.01

Mule 0.05 O.12 50 0.00-0.62 0.02-0.08 (F = 166.631

Oct.-Dec. 1987 North American Bird Bander Page 163

Age, Species, and Sex Determination of Hummingbirds (cont.)

APPENDIX R,' Netturenentt (at} of tubadult Ruby-throated Huaaingblrdu ohowing tlgnlficont differencee between taxer.

Character Confidence 619nlflconce Sex • 6,D. N Range interval (fettle vt tale)

Bill (expoted cultart}

Fettle 17.46 O.SS 25 16.30-18.65 17.23-17.69 Sis. P(O.Ol

Male 15.67 O.TB 53 13.Bo-17.90 1õ.46-1õ.99 (F = Io7.B3)

Ming (chord)

Female 40.14 0.72 26 43.30-46.25 44.85-45.43 61g. P*O.Ol

Male 41.70 1.O3 55 40.oo-40.15 41.42-41.90 (F = 23õ.õ2)

Tti] (length)

FeBtie 25.10 0.94 28 23.00-27.00 24.81-25.57 Sig. F•o.ol

Male 24.42 0.87 52 23.OO-27.OO 24.18-24.S6 (F - 12.83)

Maximum width Oth rectrix

Female 0.34 0.33 20 4.80-6.00 0.21-5.47 NS

Male 5.23 0.37 52 4.00-6.20 5.13-õ,33 (F n 1.71)

Length of .hite 5th rectrix

Fettle 6.60 0.84 25 0.30-8.95 6.25-6.95 Sis. P•O.Ol

Hale 5.60 0.75 51 4.10-7.3õ õ.44-õ.06 (F = 24.92)

Aret of white 3rd rectrlx

Fettle 14.19 3.30 26 8.67-20.87 12.86-15.52 6]g. P(O.O]

Male 3.91 2.21 52 O.O1-9.68 3.29-4.03 F = 267.08)

APPENDIX f. Mettureaentt (ta) of tubtdult Bltck-chinned Huaalngbirdt the, inS tignifictnt differencee between taxer.

Character Confidence Significance Sex • a.D. N RtnOe lntervtl (fettle vt mole)

Bill (expoted culaen)

Female 19.24 1.07 48 16.90-21.60 18.93-19.56 Sis. P(O.01

Male 17.63 1.05 36 10.00-20.00 17.28-17.98 (F - 47.10)

Ming (chord)

Female 46.03 1.06 48 43.85-48.50 45.72-46.34 Slg. P•O.O]

Melt 43.42 1.33 37 40.o5-46.8o 42.98-43.86 (F - 101.o2)

T&II (length)

Feeflu 26.71 0.99 48 23.00-28.00 20.42-26.00 SiS. P(O.O]

Hale 24.27 1.24 37 22.00-26.00 23.86-24.68 (F = 35.43)

Ntxiaum width Oth rectrix

Fettle 5.26 0.34 48 4.60-6.20 0.16-6.36 6ig. P•O.OI

Male 6.00 O.31 37 4.45-5.95 4.90-5.10 (F - 12.39)

Length of white 6th rectrin

Female 6.03 0.69 48 4.90-7.60 5.83-8.23 Sis. P(O.OI

Mule 5.00 0.69 37 4.1o-7.o5 5.27-0.73 (F - 12.07)

Area of white 3rd FaCtFiX

Female 18.83 4.18 47 10.o1-28.o7 17.60-20.o6 Sis. P<O.O]

Male 0.39 2.29 37 1.84-9.45 4.63-6.15 (F - 308.40)

Page 164 North American Bird Bander Vol. 12, No. 4

APPRNDIX 0. MeaoureBento (BB} Of Juvenile Coota'o SuBBingbirde ohowing oignificant differencee between eexeo.

Charoctet Confidence Significance SeE • S.D. M Ronge Interval (femola vo Bole)

Sill (eEpooed culBen)

Female 16.42 0.81 14 14.30-17.i0 i3.93-16.89 9ig. P(0.05

Male Jfi.71 0.98 26 13.70-17.40 15.32-16.10 (f • 5.38)

Wing (chord)

Female 44.56 0.73 24 43.05-45.65 44.14-44.98 NS

Hale 44.34 1.0l 26 42.10-46.05 43.93-44,75

Tell (length)

female 23.00 0.78 14 22.00-24.00 22.55-23.45 Sig.

Male 22.31 0.93 26 21.00-24.00 21.03-22.60 (f - 6,61)

NOElBUm width 5th FactFIE

feBelm 4.01 0.28 14 3.50-4.45 3.85-4.17 Sl9. P*0.01

MOle 3.22 0.37 26 2.40-3.95 3.07-3.37 (F - 49.71)

Length or white 5th rectriE

Female 4.92 0.90 14 3.40-6.25 4.46-5.38 Sig. P-0.01

Hale 3.55 0.47 26 2,55-4.60 3.36-3.74 (F - 47.52)

Area of white 3rd rectrix

Female 13.72 4.22 14 6.30-22.92 11.29-16.16 Sig. P(0.0I

Male 4.57 2.56 26 0.lfi-9.96 3.53-6.61

APpRNDXK S. MeaoureBenta (n) of Juvenile Anna'o HuBBingbirdo ohowing oignificant differencee between oexee.

Character Confidence Significance Sex • 9.D. M Range Interval (femole vo male}

Sill (expooed culBen)

Female

Male

Wing {chord}

Female

Male

Tall {length}

Female

Male

Maximum width 5th FactFix

Female

Male

Length of white 5th Factfix

Female

Male

Area of white 3rd FactFix

Female

Male

15.55 2,62 12 10.66-18.15 13,95-17.15 NS

14.65 1.66 3 12.90-16.00 --- (F • 0.34)

49.96 1.62 l0 47.10-52.25 48.80-63.32 NS

50.52 0.78 3 49.90-5i.40 --- (F - 0.33)

27.50 ].27 10 25.00-29.00 26.59-28.4l NS

28.00 1.73 3 26.00-29,00 --- (f ' 0.31)

5,84 0.34 II 8.40-6.45 6.6l-6.07 NS

6.15 0.39 3 6.90-6.60 --- (f - 1.88)

5.20 0.90 II 3.30-6.46 4.60-5.80 Sig. P(0.0I

3.55 0.40 3 3,16-3.95 --- (f - 9.27)

7.98 3.86 II 1.44-13.20 6.53-10.43 Sig. P•0.01

0.04 0.06 3 0.00-0.10 --- (F - 13.38)

Oct.-Dec. 1987 North American Bird Bander Page 165

Age, Species, and Sex Determination of Hummingbirds (cont.)

APPRRDIR I. Heasurements (mm) of Juvenile Ruby-throated Bummingbirds showing significant

Character Confidence Significance Sex • 8.D. R Range interval (female vs male)

Bill (expossd culmen)

Hale

Hlng (chord)

Hale

Tail (length)

Hale

Hsximum width {th FaCtFix

Female

Hale

Length of white 8th rectrlx

Female

Hale

Ares of white 3rd rectrlx

Female

Hale

15.59 0.92 18 14.80-17.85 16.08-17.10 gig. P(O.01

14.25 1.17 24 10.00-15.60 13.75-14.74 (F - 43.28)

45.64 1.28 16 42.98-47.75 44.96-46.32 91g. P(O.01

41.60 1.39 25 37.25-43.70 41.03-42.17 (F = 90.12)

25.25 0.88 16 24.00-27.00 24.79-25.71 gig. P(O.05

24.58 0.72 24 23.00-26.00 24.28-24.68 (F - ?.10)

5.28 0.22 15 4.90-5.75 5.14-5.38 R9

5.27 0.46 26 4.60-6.50 5.07-5.47 (F - 0.00)

6.82 0.84 16 6.80-9.76 6.37-7.27 SiR. P,O.01

5.88 0.49 25 4,90-6.65 5.66-6.08 (F - 20.73)

14.83 2.18 14 10.62-17.97 14.12-15.54 9ig. P•O.01

4.82 1.66 26 1.15-7.40 4.14-5.50 (F - 260.08)

APPEWDIR 3. Heasurements (am) of Juvenile Black-chJnned Hummingbirds sho•ing significsnt differences between sexes.

Character Confidence Significance Sex • S.D. R Range interval (female vs male)

Rill (exposed culmen)

Female 18.85 0.88 17 18.90-20.45 18.40-19.30 9JR. P-O.01

Hals 17.77 1.10 17 10.00-19.20 17.21-18.33 (F - 10.21)

Hlng (chord)

Female 45.57 1.12 17 44.50-48.50 45.99-47.15 SiR. P(O.O!

Hale 43.97 1.33 17 40.90-45.95 43.29-44.65 (F - 38.07)

Tail (length)

Female 28.83 0.94 11 24.00-20.00 26.04-27.02 SiR. P'O.01

Hals 28.47 1.07 17 24.00-27.00 24.92-26.02 (F - 9.38)

HaximuB width 6th rectrlx

Female 5.23 0.28 27 4.80-5.60 8.10-8.38 RS

Hale 5.10 0.30 17 4.60-5.65 4.98-5.26 (F - 1.74)

Length of white 6th FaCtFiX

Female 5.24 0.91 17 4.60-7.85 5.77-6.71 NS

Hale 5.75 0.84 17 4.60-6.95 5.43-6.09 (r" 3.29)

Area of white 3rd FactFix

Female 19.42 3.28 16 12.73-24.00 17.87-21.17 SiR. P•O.Oi

Hale 7.36 2.31 17 3.40-12.00 6.17-8.85 (F - 150.37)

Page 166 North American Bird Bander Vol. 12, No. 4